1. Technical Field of the Invention
The present invention relates to novel cosmetic/dermatological compositions for topical application to human skin, comprising sodium dehydroisoandrosterone 3-sulfate, also termed dehydro-epi-androsterone sulfate, or known by the simple abbreviation "S-DHEA," and to the use of same for treating certain signs of endogenous and/or exogenous aging.
2. Description of the Prior Art
Cutaneous aging results from the effects on the skin of intrinsic and extrinsic factors. Clinically, the signs of aging are reflected by the appearance of wrinkles and fine lines, by a slackening of cutaneous and subcutaneous tissue, by a loss of cutaneous elasticity, by atonia of the texture of the skin and by the yellowing of the skin which becomes duller and loses its radiance. On the areas of the skin which have been exposed to sunlight throughout life - essentially the face, the neckline, the hands and the forearms - pigmentation marks, telangiectasia and elastosis are often observed.
Certain of these signs are more particularly associated with intrinsic or physiological aging, namely, aging associated with age, whereas others are more specific to extrinsic aging, namely, aging caused by the environment in general; this relates more particularly to photoaging due to exposure to sunlight, to light or to any other radiation.
The changes in the skin resulting from intrinsic or physiological aging are the consequence of a genetically programmed senescence involving endogenous factors. This intrinsic aging causes, in particular, a slowing down in the rate of regeneration of skin cells. Histologically, the skin is overall rendered thinner, both at the epidermal and dermal levels. The density of the fibrous macromolecules of the dermis (elastin and collagen) is reduced. In contrast, extrinsic aging effects histopathological changes such as excessive accumulation of elastic matter in the upper dermis and degeneration of the collagen fibers.
In general, skin aging manifests itself in the appearance of wrinkles and fine lines, with the slackening of cutaneous and subcutaneous tissue and with the radiance of the skin. Slackening of the cutaneous and subcutaneous tissue is reflected in a skin texture lacking tone, slackening of the cutaneous microrelief, reduced skin firmness and an overall flaccid skin.
Numerous compositions are known to this art for treating wrinkles and fine lines on the skin or to firm skin tissue; however, these compositions provide only incomplete and temporary treatment of these morphological disorders. Thus, serious need continues to exist for a topical-application composition which makes it possible to treat wrinkles and fine lines more effectively, as well as to firm skin tissue.